Tandem wheel construction



July 16, 1940.

c. A. WICKER TANDEM WHEEL CONSTRUCTION 2 Sheets-Sheet 2 Filed June 7, 1939 gwuem bom Qua/1M0 Patented July 16, 1940 I v S PATENT OF FHIE v 2,208,484 h TANDEM WHEEL CONSTRUCTION Charles A. Wicker, Selma, Ala. I Applicationne 7, 1939, Serial No. 277,946 3Claims. (01.280-124) This invention relates to auxiliary wheel susbly being constructed in accordance with the UNIT-ED STATE.

pensions for vehicles. principles of my invention. t

An object of the invention is the provision of a Figure 2 is a transverse vertical sectiontaken spring suspension for tandem wheel construcalong the line 2-2 of Figure 1. tions in which the load of the vehicle at the Figure 3 is a transverse vertical section taken 5' rear axle will be distributed between more than on the line 3-3 of Figure l. c the customary two wheels whereby an equaliz- Figure 4 is a fragmentary longitudinal view ing eifect is had and whereby a greater load may taken along the line 4-4 of Figure 2. be carried by the vehicle with a consequent sav- Figure 5 a transverse vertical section taken. in on the tires by the, elimination of sliding along th'eline 5-5. of Figure 4, 1O and-with a consequent ease in steering." Figure 6 is a view in perspective of a plate Another object of the invention is the proand bearing aidingin supporting one end of the vision of a tandem wheel construction for vehiauxiliary springs, y 7 cles in which the load of the vehicle is not only Figure 7 is a rear view of the auxiliary wheel distributed over four tires instead of two, but the construction partly in section showing a modi- 15 construction is such that the vehicle will be able fied form of the invention. V, to turn curves without the usual sliding of the -Figure 8 is a view in perspective of a sleeve tires thus eliminating tire wear and facilitating adaptedto be received by a square axle to which the steering of the vehicle because when the is connected one end of the vehicle spring.

2i) vehicle turns a curve the same will lean to the Figure 9 is an end View of a split connection '20 outside of the curve whereby the outer springs adapted to be employed for connecting one end will expand while the springs at the inside of of. the other auxiliary Spring o a Sq e axle. the vehicle will contract with a consequence that Referring mo e p arly to the drawin the load is maintained in equilibrium and there Ii] designates a beam of the chassis of a truck is no tendency at any time to swing the body which is n ma y upp d by p u d leaf 25 outwardly due to the fact that the body will springs ll. Brackets l2 and I3 are secured in assume a predetermined position by the comspaced relation to the beam l0 and the ends ipensating effect of the springs. of the. leaf springs areisupported on bolts M A further object of the invention is the proand i5 suspended. respectively from the brackets vision of the tandem wheel construction in which p i2 andv l3 at each side of the frame. t 30 the spring suspension of the auxiliary wheels e W ed W i an axle us have cooperative connections with the spring H- The prin s H are clamped 0 the x e suspension of the main rear wheels and in which hflusirig IT by means of UrbOUJS l3 and bridgone of the springs of the auxiliary wheels will P t Nuts 0 secu e the bolts in posihave a rocking connection with the axle ,or axle tiOn W sp t0 the bridging p ate 9- 5 housing supporting the auxiliary wheels while A differe housing 5 contains the 1151181 the other spring will be rigidly connected with differential for driving the rear axles of which the axle or axle housing to compensate forvarione desi y e numeral is ow a d ations in t movement of t prings when a drive shaft housing 25 extends from the (lif turning corners or when traveling over an unfelentialr housing 40 even roadbed 7 Rear wheels 21 are mounted on the rear axles This invention will be best understood fro m 3 g gg tfi g i gi -supporting the m at a consideration of the following detailed dev F scription, in View of the accompanying draw Ail of the elemgriits ust described are standard ings forming a part of the, specification; neverequlpmen" on V6 0168 of thls type and form no theless, it is to be under stoo-d thatthe invention sf f gg g g gg ga i gg at 3| 6 the not confinedto e dlscloslire"bfemgsusceptl' beam It at each side of the frame and has a me echange/sendmodlfieatwns s define cut-out portion, as shown at 32, to receivethe .10 I10 mammal departurefmm h Sahel e u bracket [3. Thusthe plate 30 is located rear- 50.

of the invention (Expressed file appended wardly of the standard axle housing ll; claims. A bracket 35 is secured in any approved man- In'the drawings: a r l her to the pending portion 36 of the plate 30 i Figure 1 s a i e i v on oi a tandem at the outer face thereof and is provided with a {is wheel construction, thertandemwheel -assemv bearing 31 which receives a bolt 38'upon which and nuts 43. The hanger 39 is provided with notches 44 which receive the bights of the A pair of straps 45 are provided with a plurality of perforations '46 at the upper ends thereof to receive a bolt 4]. The plurality of perforations 46 permits the adjustment of the straps so that said straps may be raised or lowered when required. I

A plate 50 is provided with a sleeve I' at one end and this sleeve receives the bolt '41 whereby the straps 45 are suspended from said bolt.- It

will be noted that the plate 50 is clamped to the upper face of the compound leaf spring I l by means of the U-bolts N3, the plate [9* and the nuts 20. I

The oppositeends of the spring 40 are provided with sleeves 52and-53. Thesleeve 52 is adapted to receive a bolt 54 carried by the lower ends of the straps 45 while-the sleeve 53 is adapted to receive a'bolt 55 carried by bearings 56 projecting from i the sections of a split ring or block, generally desthe axle in the usual manner.

ignated by the numeral 51. The split ring hasits sections bolted together as shown at 58 on an auxiliary rear axle or housing 59 in which may be mounted an axle when wheels 6| are driven by the customary differential. V p

The wheels 6| are loosely mounted onthe axle 59 and are'free to revolve on this axle and support The wheels 21, however, in this form are driven in the usual manner.

or housing 59 for a 'Referring more particularly to Figure 2, it will be seen that'the shackle 51 at the left hand side is slightly difierent from the shackle or split ring 51 at the right hand side. Each ofthe shackles are formed of two members 62 and 63 which are substantially identical in construction and each section is provided'with a semi-circular portion 64 to neatly receive the axle or housing59.

The lower section 63'is also provided with a bearing in the form of apair of spaced cars 65 for supporting a pin 63' This pin is received by a bearing' 61 formed at one end of a connecting member 88 which has a reduced portion 69 weldedto the inner walls of a hollow rod m. This rod extends at an acute angle to a horizontal plane passing through the pin 65 and the opposite end of'this rod is rigidly'connected to an inserted end 55 H formed on a connecting member 12. This connecting member'is provided with a bearing to receive apin 13 carried by'the lower ends of the straps 45 and below the pin 54. A pair of, dowel pins 15 are inserted .through openings in the axle 59 and likewise through openings in the sections 62 and 63 and these pins project slightly beyond the opposite ends of the member 59 for rigidly securing the members '62 and 63 tothe axle or housing 59. i i

iAecareful inspection of Figure 2 will "show that the pins 15 are absentfrom the bearing block 51 so that this block' may slightly rock on the axle entlyexpl'ained. v

j Insteadof cylindricalflaxles shown in Figures 1 to 5, inclusivatheaxle-as shown at 15 (Fig. 7) may be rectangular in cross section and in this event thesections'l'l and 18 of the connecting means l9 betweenthe axle and thevehicle'spring 80 will have a rectilinear'opening; generally des-v signated'by the numeral 8l 'to neatly receive the purpose which will be pres--- axleso that when the sections are clamped together the member 19 will not rock on the axle but will be rigidly secured thereto as shown at the left hand side in Figure 7.

On the right hand side, however, the opening in the split bearing block 19 is circular and this circular opening receives a pair of sleeves 82 which have shoulders or ribs 83 at their outer ends and a square opening 84 located centrally thereof. The inner ends 85 of these sleeves as shown in Figure '7 are in abutting relation while the shoulder or ribs 83 will abut the side Walls of the block 19 having the central opening 84. The sleeves 82 may be held in a predetermined position on the axle 12 in any approved manner. By this construction thebearing block l9 may rock on the cooperative sleeves during expansion or contraction of the vehicle spring 89 When it is desired to positively drive the wheels 6! through the usual drive shaft connected with the engine of the vehicle an axle similar to that shown at It in Figure 1 will be located within the axle housing 59 and in that event one of the bearing blocks 51 or 5'1! is rigidly connected with the axle housing in any approved manner. The brake system, whatever type employed, Will operate on the brake drums 90 of the wheels 6 I.

erable expense is had in ordinary'trucks along various types of roads. Furthermore, in order to distribute the load and to relieve the tires of the strain auxiliary axles have been employed in connection with auxiliary wheels for aiding and supporting the load, but due to the lack of flexibility in the types of construction now on the market, a great wear on the tires is not obviated. V

In the present construction the load is not only evenly distributed on all four tires, but the particular spring suspension for the auxiliary axle and supplemental wheels, relieves the wear and tear on the tires by preventing skidding or sliding and the load is more equally distributed on all of the tires.

In the operation the auxiliary wheels 3| are connected not only to the channel beams I!) of the vehicle but they have a flexible connection with the main compound leaf springs H through the straps or shackles 45, particularly where the auxiliary springs 40 are partly supported by said shackles. These springs while being permitted to swing are limited in their swinging movement by the connections through the rods 19.

One of the wheels 6| may be elevated without disturbing the position ofthe associated wheel and rocking of the rear axle is also compensated for by the fact that the member 5! is permitted 'to' rock on the axle while the other member 51 is secured to the axle.

When the wheels are raised the rear ends of the springs 40 are likewise raised and the shackles wheels is imparted in a flexible manner to the rear wheels 6 I. r

In view of the fact that brakes are employed in connection with the auxiliary wheels 6| the axle 59 must be held against, movement and dem wheel construction comprising anauxiliary since the dowel pins hold the axle against motion the auxiliary wheels will likewise be held when the brakes are applied, although a certain amount of flexibility is provided since the beating block 5'! is permitted rocking movement on the axle and this is also true of the construction shown in Figure 7. i

In turning a curve, the vehicle swings to the outside of the curve which causes the outside spring 40 to expand while the inside spring contracts, thereby increasing the space between the outside wheels while decreasing the space between the inside wheels, expansion and contraction being necessary between the wheels of the pulling unit and the tandem unit.

When one of the wheels enters a depression or 1 moves over an elevation there is always expansion and contraction of the vehicle springs and this expansion and contraction is compensated for by the rocking of the straps 45 through the members 10 and by the rocking of the member 51* or 80 "members gives a certain amount of flexibility even though the other member'5'l or is held 7 against movement.

I claim:

1. An attachment for trucks'to provide a tandem wheel construction comprising an auxiliary axle, wheels on the axle, a pair of leaf springs, means rigidly connected with one end of the axle and havingpivotal connection at one side of the axle with one end of one spring, means rockably mounted on the other end of the axle and having pivotal connections with a similarly disposed end of the other spring, shackles adapted to be pivotally suspended at one end from a part of the truck, rods rigidly connecting both means on the axles to the other ends of the shackles and at diametrically opposite points from the spring This rocking movement of these;

other ends of the springs to intermediate portions of said shackles, and means for supporting the springs from the truck.

2. An attachment for trucks to provide a tantruck, means located below the axle and each of the springs rigidly connecting the rigid means and the rockable means on the axle with the swingable means, and means adapted to connect intermediate portions of the springs with the frame of the truck.

3. A tandem wheel construction for trucks having leaf springs connecting the usual rear axle housing to the chassis frame comprising a unit adapted to be removably connected to the rear end of the truck and including an auxiliary axle, a pair of auxiliary leaf springs, a block rigid with one end of the auxiliary axle, means pivotally connecting the outer end of one auxiliary spring with the upper end of the block, a second block rockably mounted on the other end of the auxiliary axle, means pivotally connecting the outer end of the other spring with the upper end of the iliary axle, means connecting theintermediate portions of the auxiliary springs with the frame,

and means pivotally supporting the upper ends of the shackles on the first-mentioned springs. CHARLES A. WICKER. 

